Authentication of shock therapy deferral

ABSTRACT

The current technology relates to a shock deferral unit that is portable by an ambulatory patient. The shock deferral unit has a bi-directional communication device configured to receive a notification of an impending shock from a defibrillator and configured to send an instruction to defer the impending shock to the defibrillator. An authentication interface is configured to receive authentication data from a user. A user instruction interface is configured to receive the instruction to defer the impending shock from the user. An authentication device is configured to authenticate the user based on the authentication data and instruct the bi-directional communication device to send the instruction to defer a shock upon authentication and receipt of the instruction to defer the shock.

This application claims the benefit of U.S. Provisional Application No.62/331,047, filed May 3, 2016, the contents of which are hereinincorporated by reference.

FIELD OF THE TECHNOLOGY

The technology disclosed herein generally relates to shock therapydeferral. More particularly, the technology disclosed herein relates tosystems and methods for authentication of shock therapy deferral.

BACKGROUND

In spite of the many advances in tachyarrhythmia discrimination inimplantable and wearable defibrillators, there are still instances whendelivery of shock therapy is inappropriate. Inappropriate shocks arepainful and in some cases hazardous to the patient. On the other hand,failure to deliver an appropriate shock treatment is also hazardous tothe patient. Allowing patients and caregivers to defer an impendingshock treatment is generally desirable to avoid inappropriate shocks,but challenges include reducing the risk to the patient that human erroror inadvertent interaction with the system results in inappropriateshock deferral.

SUMMARY

Some aspects of the technology disclosed herein relate to a shockdeferral unit that is generally portable by an ambulatory patient. Abi-directional communication device is configured to receive anotification of an impending shock from a defibrillator and configuredto send an instruction to defer the impending shock to thedefibrillator. An authentication interface is configured to receiveauthentication data from a user. A user instruction interface isconfigured to receive the instruction to defer the impending shock fromthe user, and an authentication device is configured to authenticate theuser based on the authentication data and instruct the bi-directionalcommunication device to send the instruction to defer a shock uponauthentication and receipt of the instruction to defer the shock.

According to some examples, the bi-directional communication device is aradio. In addition or alternatively, the shock deferral unit has a userinterface configured to display the notification of the impending shock.In addition or alternatively, the shock deferral unit is configured tobe pocketable by a patient. In addition or alternatively, the shockdeferral unit is configured to be worn by patient. In addition oralternatively, the shock deferral unit is configured to be at least onein the group consisting of: wearable by, manually holdable by, andpocketable by a patient. In addition or alternatively, theauthentication interface is configured to receive at least one type ofauthentication data from the user in the group consisting of: textual,verbal, haptic, and biometric data. In addition or alternatively, thebi-directional communication device is configured to relay one or morephysiological measurements sensed by the defibrillator to the userinterface. In addition or alternatively, the bi-directionalcommunication device is configured to communicate a notification of anarrhythmia sensed by the defibrillator.

Other aspects of the present technology relate to a shock deferralsystem. A defibrillator is configured to sense patient physiologicalmeasures, communicate a notification of impending shock, and delivershock therapy. A bi-directional communication device may be configuredto receive a notification of impending shock from the defibrillator andconfigured to send an instruction to defer the impending shock to thedefibrillator. An authentication interface may be configured to receiveauthentication data from a user. A user instruction interface may beconfigured to receive the instruction to defer the impending shock fromthe user. An authentication device may be configured to receive theauthentication data from the authentication interface, and authenticatethe user based on the authentication data, where the defibrillator isconfigured to defer shock upon authentication by the authenticationdevice and receipt of the instruction to defer the shock, wherein theauthentication interface and the user instruction interface are portableby an ambulatory patient.

According to some examples, the defibrillator comprises theauthentication device. In addition or alternatively, the authenticationinterface is configured to receive authentication data from a user andthe user instruction interface is configured to send the instruction todefer shock within a 60-second time period. In addition oralternatively, the authentication device is configured to authenticatethe user each time the shock deferral unit receives a notification ofimpending shock from the defibrillator. In addition or alternatively,the bi-directional communication device is configured to relay one ormore physiological measurements sensed by the defibrillator to a userinterface.

Another aspect of the present technology relates to a method. Anotification of impending shock therapy is relayed from a defibrillatorto a user interface, wherein the user interface is portable by anambulatory patient. Authentication data is received from a user throughan authentication interface in response to relaying the notification.The user is authenticated with the received authentication data. Aninstruction is received from the user to defer the impending shocktherapy through a user input device. The received instruction is sent tothe defibrillator to defer the impending shock therapy uponauthentication.

According to some examples, a remaining deferral time is communicatedafter sending the received instruction to the defibrillator to defer theimpending shock therapy. In addition or alternatively, receivingauthentication data from a user occurs within 60 seconds of relaying thenotification of impending shock. In addition or alternatively, theauthentication interface is a biometric sensor. In addition oralternatively, the authentication interface is a manual user data entrydevice. In addition or alternatively, the authentication interface is atleast one in the group consisting of: a biometric sensor, a microphone,and a manual user data entry device. In addition or alternatively, anotification of at least one of: physiological measurements sensed bythe defibrillator and shock deferral status, is relayed to the userinterface. In addition or alternatively, a notification of an arrhythmiasensed by the defibrillator is relayed to the user interface. Inaddition or alternatively, the instruction from the user is receivedthrough at least one of: a watch, a pendant, a bracelet, eyeglasses,headphones, a mobile phone, a pen, a card, a box, and an adhesiveaccessory. In addition or alternatively, the instruction from the useris received through at least one of: a wearable device and a pocketabledevice. In addition or alternatively, the received instruction to thedefibrillator is sent through radio frequency. In addition oralternatively, a training mode is entered comprising soliciting a userfor authentication data absent a notification of impending shocktherapy.

BRIEF DESCRIPTION OF THE DRAWINGS

The current technology may be more completely understood and appreciatedin consideration of the following detailed description of variousexamples of the current technology in connection with the accompanyingdrawings.

FIG. 1 depicts an example implementation of a shock deferral systemconsistent with the technology disclosed herein.

FIG. 2 is a flow chart consistent with some examples of the technologydisclosed herein.

FIG. 3 is an example implementation of a shock deferral unit consistentwith the technology disclosed herein.

FIG. 4 depicts another example implementation of a shock deferral unitconsistent with the technology disclosed herein.

FIG. 5 is a schematic diagram of components of a defibrillator accordingto some embodiments.

DETAILED DESCRIPTION

Implantable and wearable defibrillators have saved many lives byproviding shock therapy to patients who are experiencing heartfibrillations. However, there are instances when defibrillators delivershock therapy inappropriately, and these issues occur withdefibrillators from many different manufacturers and using manydifferent therapy algorithms. Inappropriate shocks are painful, oftenfeeling similar to being kicked in the chest, and can be traumatic forthe patient. An inappropriate shock can also be hazardous to thepatient. On the other hand, failure to deliver an appropriate shocktreatment is also hazardous to the patient.

Allowing patients and trained caregivers to defer an impending shocktreatment is generally desirable to avoid inappropriate shocks. If apatient is conscious and lucid enough to operate a shock deferraldevice, it is likely medically acceptable to defer the shock. But it isa challenge to reduce the risk of an inappropriate shock deferral thatcan result from human error, especially from an untrained caregiver orpasser-by, or from an inadvertent interaction with the system, such asin situations where the patient collapses and an object makes contactwith the system in a way that instructs the system to defer the shock.Also, receiving a warning of an impending shock is a stressful situationfor a patient and for a caregiver.

Systems and methods are described herein that provide an option to defera shock and authenticate the user who is deferring the shock, therebyreducing the risk that the shock is deferred when it should bedelivered. Many of the systems and methods described authenticate theuser in a manner that is relatively simple to operate in a stressfulsituation.

FIG. 1 depicts an example implementation of a system consistent with thetechnology disclosed herein. The system has a defibrillator 110implanted in communication with a patient's heart 105 and a shockdeferral unit 170 in bi-directional communication with the defibrillator110. While a transvenous implantable defibrillator is described herein,it will be understood that in some embodiments the defibrillator couldbe a subcutaneous implantable defibrillator or a defibrillator externalto the patient. For example, the defibrillators can be worn by thepatient in some embodiments.

The defibrillator 110 is generally configured to sense patientphysiological measures, identify when shock therapy is appropriate basedon the physiological data, and deliver shock therapy when appropriate.The defibrillator 110 generally has a plurality of sensors that areconfigured to sense patient physiological measures. The sensors can beone or more leads 108A-C that are configured to sense an electriccurrent and deliver an electric current to a patient's heart 105.Cardiac leads 108A-C have a proximal end that is coupled to a header 155of the defibrillator 110 and a distal end coupled by an electrode orelectrodes to one or more portions of the heart 105. The electrodes areconfigured to deliver defibrillation therapy, but can additionally beconfigured to deliver cardioversion, pacing, resynchronization therapy,or combinations thereof to at least one chamber of the heart 105. Theelectrodes may be electrically coupled to sense amplifiers to senseelectrical cardiac signals.

By way of background, the heart 105 generally has a right atrium 100A, aleft atrium 100B, a right ventricle 105A, a left ventricle 105B, and acoronary sinus extending from the right atrium 100A. The atrial lead108A has electrodes (electrical contacts, such as ring electrode 125 andtip electrode 130) disposed in the right atrium 100A of heart 105 forsensing signals from, and/or delivering pacing therapy to, the rightatrium 100A.

The ventricular lead 108B has one or more electrodes, such as tipelectrode 135 and ring electrode 140, for sensing signals, deliveringpacing therapy, or both sensing signals and delivering pacing therapy.The ventricular lead 108B optionally also has additional electrodes,such as for delivering atrial cardioversion, atrial defibrillation,ventricular cardioversion, ventricular defibrillation, or combinationsthereof to the heart 105. Such electrodes typically have larger surfaceareas than pacing electrodes in order to handle the larger energiesinvolved in defibrillation. The ventricular lead 108B optionallyprovides resynchronization therapy to the heart 105.

The defibrillator 110 can have a third cardiac lead 108C attached to thedefibrillator 110 through the header 155. The third cardiac lead 108Ccan have ring electrodes 160, 165 placed in a coronary vein lyingepicardially on the left ventricle (LV) 105B via the coronary vein.

The second cardiac lead 108B can have a first defibrillation coil 175located proximal to tip and ring electrodes 135, 140 for placement in aright ventricle (RV), and a second defibrillation coil electrode 180located proximal to the first defibrillation coil 175, tip electrode135, and ring electrode 140 and configured for placement in the superiorvena cava (SVC). In some examples, high-energy shock therapy isdelivered from the first or RV coil 175 to the second or SVC coil 180.In some examples, the SVC coil 180 is electrically tied to an electrodeformed on a hermetically-sealed defibrillator can 150. This improvesdefibrillation by delivering current from the RV coil 175 more uniformlyover the ventricular myocardium. In some examples, the therapy isdelivered from the RV coil 175 only to the electrode formed on thedefibrillator can 150. In some examples lead 108B does not haveelectrode 140 and the pacing and sensing functions of electrode 140 areperformed by RV coil 175.

Other forms of electrodes include meshes and patches which can beapplied to portions of heart 105 or which can be implanted in otherareas of the body to help “steer” electrical currents produced bydefibrillator 110. The present methods and systems will work in avariety of configurations and with a variety of sensors. Sensing amongdifferent sets of electrodes often provides directional informationregarding the propagation of cardiac signals and is often referred to assensing among different vectors. For example, in a single chamber ICD,sensing from a right ventricular tip electrode 135 to a rightventricular ring electrode 140 would be a first vector, and sensing froman RV coil 175 to an electrode on the defibrillator can 150, or a header155, would be second vector. Various electrode configurations may beused.

EGM data can be collected for at least the right ventricular channel,with electrodes implanted in or near a ventricle. For example, aventricular channel or vector may have a tip electrode and ringelectrode for the right ventricular channel or ring electrodes for theleft ventricular channel. Another channel, known as the shock channel orshock vector, can be used to collect EGM data. The shock channel issensed using electrodes that are also used to deliver high-energy shocktherapy. In one example, the shock channel has an electrode placed inthe right ventricle.

The electrode configuration of defibrillators 110 used in the systemsand methods described herein generally allow for the collection ofpatient cardiac data such as electrograms (EGMs), identify an arrhythmiafrom the patient cardiac data and deliver high-energy shock therapy to apatient's heart upon detection of the arrhythmia. The defibrillator 110is also configured for bi-directional, wireless communication with theshock deferral unit 170. In some embodiments the defibrillator 110 has aradio allowing bi-directional communication via radio frequency. Thedefibrillator 110 is generally configured to communicate a notificationof an impending shock to the shock deferral unit 170. The defibrillator110 is generally configured to receive an instruction to defer animpending shock from the shock deferral unit 170. The defibrillator 110is generally configured to defer an impending shock upon receipt of aninstruction to defer the impending shock and authentication of the userinstructing the system to defer the impending shock, which will bedescribed in more detail, below. In some embodiments the defibrillator110 is configured to communicate one or more physiological measurementssensed by the defibrillator 110, such as communicating a notification ofa sensed arrhythmia to the shock deferral unit 170.

The shock deferral unit 170 is generally configured to notify a user ofan impending shock from the defibrillator 110 and send a userinstruction to optionally defer the shock to the defibrillator 110. Theuser may be, for example, the defibrillator patient, someone typicallyresiding with the patient (e.g. the patient's spouse), a physician, anurse, someone with minimal training caring for the patient (e.g. anursing home attendant or personal care attendant) or a Good Samaritanencountering the patient at a critical time.

The shock deferral unit 170 can have a variety of configurations andimplementations, but is generally portable by an ambulatory patient.Such a configuration can be desirable to enable the patient being inclose proximity to the shock deferral unit 170 a majority of the time.The term “portable” means capable of being carried or moved by anambulatory patient. In some embodiments the shock deferral unit 170 hasno single outer dimension larger than 15 centimeters. In addition oralternatively, the shock deferral unit 170 has a weight of 3 kilogramsor less. In addition or alternatively, the shock deferral unit has nosingle outer dimension larger than 5 centimeters. In addition oralternatively, the shock deferral unit 170 has a weight of 1 kilogram orless. In some embodiments the shock deferral unit is configured to bewearable by a patient. As used herein, the term “wearable” means capableof being attached to a body part of a patient or to a patient's clothingwithout interfering with walking. In addition or alternatively, theshock deferral unit is configured to be pocketable by the patient. Inaddition or alternatively, the shock deferral unit is configured to beholdable by the patient. The particular optional configurations of theshock deferral unit will be described in more detail with reference toFIGS. 3-4.

Returning to FIG. 1, the shock deferral unit 170 generally has abi-directional communication device 172, a user interface 171, a userinstruction interface 174, an authentication interface 176, and anauthentication device 178. While the shock deferral unit 170 is depictedas a single component, in multiple embodiments the shock deferral unit170 can be multiple components. In various embodiments each of thebi-directional communication device 172, the user interface 171, theuser instruction interface 174, the authentication interface 176 and theauthentication device 178 are configured to be portable by an ambulatorypatient.

The bi-directional communication device 172 is generally configured forbi-directional communication with the defibrillator 110, generallythrough wireless signals 190 with the defibrillator 110. Thebi-directional communication device 172 can have a radio. The wirelesssignals 190 can be radio frequency (RF), inductive, conductive or othertelemetry signals. The bi-directional communication device 172 isgenerally configured to receive a notification of impending shock from adefibrillator 110 and also configured to send an instruction to deferthe shock to the defibrillator 110, where the instruction was receivedfrom a user.

The bi-directional communication device 172 can also be configured torelay one or more physiological measurements sensed by the defibrillator110. For example, the bi-directional communication device 172 can beconfigured to communicate a notification of an arrhythmia sensed by thedefibrillator, in a variety of embodiments. In another example, thebi-directional communication device 172 can be configured to communicatephysiological measures such as heart rate, blood pressure, respirationrate, activity level, and combinations thereof.

In some embodiments, the bi-directional communication device 172communicates with the defibrillator 110 at scheduled intervals todownload patient physiological data from the defibrillator. For example,the bi-directional communication device 172 can download patientphysiological data from the defibrillator every 10 minutes, 5 minutes, 1minute, or less. In some embodiments, the bi-directional communicationdevice 172 communicates in real time with the defibrillator 110. Invarious embodiments, the defibrillator 110 and the bi-directionalcommunication device 172 communicate in real time at least in the eventof an impending shock.

The bi-directional communication device 172 can send data from thedefibrillator 110 to the user interface 171 for display on the userinterface 171, in a variety of embodiments. The user interface isgenerally configured to provide output data to a user. In a variety ofembodiments the user interface 171 is a display screen, but the userinterface 171 can also incorporate speakers, haptic, or other outputs tocommunicate data to a user. In a variety of embodiments the userinterface 171 is configured to display the notification of impendingshock received by the bi-directional communication device 172. In someembodiments, the user interface 171 is configured to display one or morephysiological measurements, such as a notification of arrhythmia, sensedby the defibrillator 110 and relayed by the bi-directional communicationdevice 172. Upon deferring an impending shock therapy, the userinterface 171 is configured to communicate the deferral time remainingbefore the next impending shock therapy.

While in the current embodiment the user interface 171 is depicted as acomponent of the shock deferral unit 170, in some embodiments the userinterface 171 is a separate device from the shock deferral unit 170. Insuch embodiments the shock deferral unit 170 and the user interface 171are each configured to be portable by an ambulatory patient. Forexample, the user interface 171 can be a smart-phone that is incommunication with the shock deferral unit 170.

The user instruction interface 174 of the shock deferral unit 170 isgenerally configured to receive an instruction to defer an impendingshock from a user. In some embodiments the user instruction interface174 can be configured to receive various types of user data as aninstruction to defer an impending shock. For example, the userinstruction interface 174 can be a manual data entry device such as aphysical or virtual button. In other examples, the user instructioninterface 174 is a microphone configured to receive a user's verbalinstruction to defer shock. The verbal instructions to defer shock canbe spoken phrases from a patient such as “don't shock me” or “defershock.”

In a variety of embodiments, when the user interface 171 notifies theuser of the impending shock from the defibrillator 110, the userinterface 171 also prompts the user for an instruction to defer theimpending shock. While in the current embodiment the user instructioninterface 174 is depicted as a component of the shock deferral unit 170,in some embodiments the user instruction interface 174 is a separatedevice from the shock deferral unit 170. In such embodiments the shockdeferral unit 170 and the user instruction interface 174 are eachconfigured to be portable by an ambulatory patient. In some embodimentsthe user instruction interface 174 and the user interface 171 can beincorporated in a single component, such as a smartphone, that isseparate from the shock deferral unit 170.

The authentication interface 176 of the shock deferral unit 170 isgenerally configured to receive authentication data from the user whoenters the instruction to defer the shock therapy. The authenticationdevice 178 is generally configured to receive the authentication datafrom the authentication interface 176 and authenticate the user based onthe user authentication data. Upon authentication, in variousembodiments, the authentication device 178 instructs the bi-directionalcommunication device to send the instruction to defer a shock uponreceipt of the instruction to defer the shock. The authenticationinterface 176 and the authentication device 178 are generally configuredto authenticate the user each time the shock deferral unit 170 receivesa notification of impending shock from the defibrillator 110.

The authentication interface 176 is generally configured to be portableby an ambulatory patient. The authentication interface 176 can beconfigured to receive various types of user data to authenticate theidentity of the user. For example, the authentication interface 176 canbe a biometric sensor configured to receive biometric data toauthenticate the identity of the user. As another example, theauthentication interface 176 can be an input configured to receive codeddata from the user, such as a manual user data entry device such as akeypad, a keyboard, buttons, or a touch screen, as examples. In generalthe authentication interface 176 authenticates the user upon anaffirmative act by the user to authenticate himself/herself. If the useris the patient within whom the defibrillator is implanted, the patient'saffirmative act of entering authentication data can be an indicator thatthe patient is hemodynamically stable and is, therefore, sufficientlyconscious and lucid to defer the impending shock therapy. If the user isa caregiver such as a family member, authentication of the user is anindicator that the caregiver has been properly trained to defer animpending shock. Authentication of the user is generally accomplished inreal time relative to notification of impending shock and receipt of theinstruction to defer shock. In this way, authentication can ensure thatthe instruction to defer shock was an affirmative act by the user ratherthan the result of an accidental or malicious act.

Biometric data used to authenticate the identity of a user can beelectrical, visual, mechanical, acoustic, and/or chemical biometricdata. Some examples of electrical biometric data that can be collectedby the authentication interface 176 for user authentication are userEKG, EEG, EOG, and EMG data. In such embodiments the authenticationinterface 176 can have one or more electrodes. Another example ofelectrical biometric data that can be collected for user authenticationis the impedance at least partially through the body of the user. Insuch embodiments the authentication interface 176 can have twoelectrodes: a first electrode configured to make contact with apatient's body at a first location and a second electrode configured tomake contact with the patient's body at a second location to define anelectrical pathway from the first location to the second location. Someexamples of visual biometric data that can be collected for userauthentication by the authentication interface 176 are images of theuser's iris, face, hand, ear, skin, and fingerprint. In such embodimentsthe authentication interface 176 can have a camera, scanner, or othervisual sensor such as a fingerprint sensor.

Some examples of mechanical biometric data that can be collected foruser authentication by the authentication interface 176 are the user'sheartbeat, blood flow, respiration and airflow. In such embodiments theauthentication interface 176 can have a mechanical sensor to collectsuch user data. Some examples of acoustical biometric data that can becollected by the authentication interface 176 are the user's heart,respiration, and voice. In such embodiments the authentication interface176 can have a microphone to collect such user data. Some examples ofchemical biometric data that can be collected for user authentication bythe authentication interface 176 are DNA, breath, tissue, saliva, blood,sweat, and tears. In such embodiments the authentication interface 176can have a chemical sensor or an electrochemical sensor to collect suchuser data.

Coded data used to authenticate the identity of the user can be textual,verbal, and/or haptic data entered by the user. Some examples of textualdata that can be collected by the authentication interface 176 for userauthentication are a textual password and a textual response to a query.In such embodiments the authentication interface 176 can have akeyboard, keypad, or touchscreen. Some examples of verbal data that canbe collected by the authentication interface 176 for user authenticationare a verbal password and a verbal response to a query. In suchembodiments the authentications interface 176 can have a microphone.Some examples of haptic data that can be collected by the authenticationinterface 176 for user authentication are a touch pattern and touchsequence. In such embodiments the authentication interface 176 can havea touch screen or touch pad.

In some embodiments the authentication interface 176 and the userinstruction interface 174 is the same component or combinations ofcomponents. In some embodiments the authentication interface 176, theuser instruction interface 174, and the user interface 171 are a singlecohesive component or combinations of components. For example, theauthentication interface 176, the user instruction interface 174 and theuser interface 171 can be defined by a keypad and corresponding screen.In the authentication interface 176, the user instruction interface 174and the user interface 171 can be defined by a touchscreen.

The authentication device 178 is configured to authenticate a user basedon the authentication data received from the user through theauthentication interface 176. In some embodiments, the authenticationdevice 178 is configured to instruct the bi-directional communicationdevice to send an instruction to defer a shock upon authentication ofthe user and upon receipt of the instruction to defer the shock. In avariety of embodiments the authentication device 178 can be incommunication with a memory or other data source that has comparisondata. The comparison data can be matched to the authentication datainput by the user to authenticate the user. In one embodiment, thecomparison data is EKG data sensed by the defibrillator. In anotherembodiment, the comparison data is a passcode or a touch-screen patternstored in memory.

In embodiments where the user instruction interface 174, theauthentication interface 176 and the user interface 171 are combinedinto a single component separate from the bi-directional communicationdevice 172, all or part of the authentication device 178 can beincorporated into either component. In some embodiments the userinstruction interface 174, the authentication interface 176, theauthentication device 178, and the user interface 171 can beincorporated into the functionality of a smart phone or a watch (asexamples) and the bi-directional communication device 172 can be anintermediary component that relays communication between thedefibrillator 110 and the smart phone. Other implementations will bedescribed below with reference to FIGS. 3-4.

Although the embodiment in FIG. 1 shows the authentication device 178separate from the defibrillator 110, in some embodiments all or part ofthe authentication device 178 resides in the defibrillator 110. In suchembodiments the defibrillator 110 is configured to defer shock uponreceipt of the instruction to defer shock and user authentication. Forexample, the authentication device 178 can be configured to receive theinstruction to defer shock from the bi-directional communication device172 and cause the defibrillator to defer shock upon authentication ofthe user.

FIG. 2 is a flow chart consistent with some embodiments of thetechnology disclosed herein. The system generally monitors the patient210. If shock therapy is indicated 220, the system displays a deferraloption 230 on the user interface. If shock therapy is not indicated 220,the system continues to monitor the patient 210. Upon display of thedeferral option 230, the system delivers shock therapy 250 if a deferralinstruction is not received 240 and defers shock therapy 260 is thedeferral instruction is received 240. Upon deferral of shock therapy260, the system monitors the patient 210 and if shock therapy is stillindicated 220 and if the system receives a second deferral instructionbefore timeout 240, then the next impending shock is deferred. If thesystem does not receive a second deferral instruction before timeout240, then the next impending shock is delivered 250.

The defibrillator generally determines whether shock therapy isindicated 220 through analysis of the patient physiological measurescollected by the defibrillator. When shock therapy is indicated 220, theshock deferral unit relays a notification of the impending shock therapyfrom the defibrillator to the user interface. The notification can be avisual and/or audio notification. The user interface will generallydisplay the deferral option 230 to the user, which provides the user theoption of deferring the shock therapy if it is appropriate. Generallythe user interface will provide the option to defer shock to the userwithin a relatively short time period following the notification ofimpending shock therapy, after which the defibrillator will deliver theshock treatment. In some embodiments the user interface displays thedeferral option to the user for 90 seconds following the notification ofimpending shock therapy. In some embodiments the user interface displaysthe deferral option to the user for 60 seconds following thenotification of impending shock therapy. In some embodiments the userinterface displays the deferral option to the user for 15 secondsfollowing the notification of impending shock therapy. In a number ofembodiments the user interface displays the amount of time the user hasto defer the impending shock therapy.

A deferral instruction is received 240 from the user when the shockdeferral unit receives an instruction from the user to defer theimpending shock through a user input device. In a variety ofembodiments, the deferral instruction is received 240 by thedefibrillator only after also receiving authentication data from theuser through an authentication interface and authenticating the userwith the received authentication data. As such, in some embodiments thesystem receives authentication data from the user within 90 seconds, 60seconds, or 15 seconds of relaying the notification of impending shockfrom the defibrillator to receive the deferral instruction 240.

In some embodiments entering the instruction to defer shock and enteringthe authentication data by the user is the result of a single input bythe user. For example, where the user instruction interface is a buttontouched or pressed by the user, the authentication interface can be afingerprint sensor to authenticate the user via fingerprint, such thatthe act of instructing the system to defer shock therapy alsoauthenticates the user. In addition or alternatively, where the userinstruction interface is a button touched or pressed by the user, theauthentication interface can have an impedance sensor and define abridge for an electrical pathway through the patient's body. Theimpedance sensor can measure the impedance through the electricalpathway to authenticate the user such that the act of instructing thesystem to defer shock therapy also provides verification that theindividual wearing the user instruction interface is the same individualwho is touching the button. As another example, where the userinstruction interface is a microphone configured to receive a user'sverbal instruction to defer shock, the authentication interface canauthenticate the user based on the user's voice. In some embodimentsentering the instruction to defer shock and entering the authenticationdata by the user is the result of multiple inputs by the user, such astouching/pressing a button to instruct the system to defer shock andentering a passcode for authentication.

Upon receiving the instruction to defer shock and authenticating theuser, the shock deferral unit sends the received instruction to defershock to the defibrillator. The received instruction can be sent to thedefibrillator through radio frequency wireless signals, for example.Upon deferral of the shock therapy 260, the system defers the shock fora predetermined period of time following receiving the instruction todefer the impending shock if shock therapy is still indicated 220. Thepredetermined period of time is referred to herein as the “deferraltime.” The deferral time can be less than or equal to 60 seconds, lessthan or equal to 45 seconds, or less than or equal to 15 seconds. Withinthe deferral time, the patient is again monitored 210 and if shocktherapy is still indicated 220 the deferral option is displayed 230again and the user instruction interface can be configured to receive asecond user instruction to again defer the impending shock.

After sending the received instruction to the defibrillator to defer theimpending shock therapy, the system can be configured to communicate theremaining deferral time to the user. Upon expiration of the deferraltime, if no second user instruction to defer shock has been received240, and if shock therapy is still indicated 220 by patientphysiological measures, the defibrillator delivers the shock therapy250. If a second deferral instruction is received 240 within thedeferral time, shock therapy is deferred 260 a second time and thepatient is monitored 210 to determine whether shock therapy is indicated220, and the process is repeated. In some examples there can be a limiton the number of deferrals or the aggregate deferral time for individualcardiac events. In other examples there is no limit to the number ofdeferrals or the aggregate deferral time.

FIG. 3 is an example implementation of a shock deferral unit 300consistent with the technology disclosed herein. The shock deferral unit300 is configured to be in bi-directional communication with animplantable or wearable defibrillator (see, for example, FIG. 1) toreceive notification of impending shock from the defibrillator and tosend an instruction to the defibrillator to defer an impending shock.The shock deferral unit 300 relays the notification of impending shockfrom the defibrillator to the user interface 310. The shock deferralunit 300 can have a bi-directional communication device that enablessuch functionality.

In the embodiment of FIG. 3, the shock deferral unit 300 is wearable bya user. In particular, the shock deferral unit 300 has a wrist strap 320that is configured to receive the wrist of a user. The user can be apatient having an implantable or wearable defibrillator. The userinterface 310 is configured to display information to the user. The userinterface 310 is configured to display the notification of impendingshock 306. The user interface 310 is configured to display one or morepatient physiological measurements, such as user heart rate 302 andblood pressure 304. The physiological measurements can be collected bythe shock deferral unit 300 itself or the physiological measurements canbe those sensed by the defibrillator and relayed to the shock deferralunit 300. The user interface 310 is configured to display the option todefer shock 308 to the user.

In the embodiment of FIG. 3, the user interface 310 is also a userinstruction interface configured to receive the instruction to defershock from the user. The user interface 310 can be a touch-screen, wherea user contacts or presses the “defer shock” display area 308 on theuser interface 310 to select it. In embodiments, the user interface 310is also an authentication interface configured to receive authenticationdata from the user. For example, the user interface 310 can incorporatea fingerprint sensor to collect user fingerprint data when the “defershock” display area 308 option is selected. In addition oralternatively, the user interface 310 can incorporate an impedancesensor configured to take an impedance measurement through the patient'sbody upon contact with the “defer shock” button 308 on the userinterface 310. In such an embodiment, the shock deferral unit 300 servesas a bridge of an electrical pathway through the user's body. Forexample, a first electrode can be disposed on the inside surface of thewrist strap 320 to make contact with the patient's wrist, and a secondelectrode can be defined by the “defer shock” button 308 such that whena patient wears the wrist strap 320 and selects the “defer shock” button308 an electrical pathway through the patient's body is created. Theimpedance of the electrical pathway can be measured by an impedancesensor for authentication of the user. In some embodiments the userinstruction interface and/or the authentication interface can be aphysical button adjacent to the “defer shock” option 308 displayed onthe user interface 310.

Although not visible in the current figure, the shock deferral unit 300generally has an authentication device that is configured toauthenticate the user based on the user authentication data. Theauthentication device can be in communication with memory havingcomparison data. The authentication device can be configured to comparethe comparison data with the authentication data and authenticate theuser when the comparison data and the authentication data matches. Uponauthentication, the authentication device is configured to allow areceived instruction to defer shock to be sent to the defibrillator.

While in the embodiment of FIG. 3 the shock deferral unit 300 has asimilar configuration to a wrist watch, alternate configurations andadditional features are certainly possible. Generally the shock deferralunit is portable by an ambulatory patient. The shock deferral unit canbe configured to be worn by a patient, pocketable by a patient, and/orgrasped by a patient's hands. The shock deferral unit being wearable bya patient can encompass embodiments where the shock deferral unit isadherable to the patient, such as adherable to the patient's skin. Insuch embodiments the electronic components of the shock deferral unitcan be re-used, but the adhesive portion can be replaced. In alternateembodiments the shock deferral unit can be at least one of: a watch, apendant, a bracelet, eyeglasses, headphones, a mobile phone, a pen, acard similar in size to a credit card, a box, and an adhesive accessory.

FIG. 4 depicts another example implementation of a shock deferral unit400 consistent with the technology disclosed herein. The shock deferralunit has multiple components, in the current embodiment: a defibrillatorinterface unit 410 and a user interface device 420 that are inbi-directional wireless communication. The defibrillator interface unit410 and the user interface device 420 can be in bi-directional wirelesscommunication via Bluetooth or radio communication, as examples. Theuser interface device 420 can be a smart phone. The defibrillatorinterface unit 410 has a bi-directional communicator (not visible) thatis configured to be in bi-directional wireless communication with animplantable or wearable defibrillator (see, for example, FIG. 1) toreceive notification of impending shock from the defibrillator and tosend an instruction to the defibrillator to defer an impending shock.The defibrillator interface unit 410 relays the notification ofimpending shock from the defibrillator to the user interface 421.

In the current embodiment the defibrillator interface unit 410 iswearable by a user. In particular, the defibrillator interface unit 410has a wrist strap 414 that is configured to receive the wrist of a user.The user can be a patient having an implantable or wearabledefibrillator. The defibrillator interface unit 410 has an optionalviewing window 412 that can display the time or other data to the user.

The user interface device 420 has a touch screen user interface 421 thatis configured to display information to the user. The user interface 421is configured to display the shock deferral status 426, which includesthe remaining deferral time 428 after instructing the defibrillator todefer an impending shock. The user interface 421 is configured todisplay one or more patient physiological measurements, such as userheart rate 422 and blood pressure 424. Such physiological measurementscan be collected by the defibrillator interface unit 410 itself or thephysiological measurements can be those sensed by the defibrillator andrelayed to the user interface device 420 from the defibrillatorinterface unit 410. The user interface 421 is configured to display theoption to defer shock 430 to the user.

Similar to the embodiment described with respect to FIG. 3, the userinterface 421 can also be a user instruction interface configured toreceive the instruction to defer shock from the user and/or anauthentication interface configured to receive authentication data fromthe user. Although not visible in the current figure, either thedefibrillator interface unit 410 or the interface device 420 has anauthentication device that is configured to authenticate the user basedon the received user authentication data, as described above. Uponauthentication, the authentication device is configured to allow areceived instruction to defer shock to be sent to the defibrillator.

FIG. 3 depicts an example user interface after notification of impendingshock therapy and FIG. 4 depicts an example user interface after theimpending shock therapy had been deferred. Prior to the shock deferralunit notifying a user of an impending shock, the user interface will notprovide an option to defer a shock and instead can provide other datasuch as respiration rate, activity level, and time and date, asexamples. Following delivery of shock therapy by the defibrillator, theuser interface can display a notification that the shock therapy wasdelivered and provide additional patient physiological data not limitedto heart rate, blood pressure, and respiration rate, as examples.

In some embodiments it can be desirable for the shock deferral unit tobe used in the training of patients and caregivers. As such, shockdeferral units consistent with the technology disclosed herein canoperate in a training mode in which the trainee is solicited forauthentication data and/or a shock deferral instruction absent anotification of impending shock therapy from the defibrillator. Patientsand caregivers can practice entering in authentication data.

Referring now to FIG. 5, some components of an exemplary defibrillator1600 are schematically illustrated. The defibrillator 1600 can have acontroller made up of a microprocessor 1610 communicating with a memory1612, where the memory 1612 can have a ROM (read-only memory) forprogram storage and a RAM (random-access memory) for data storage. Thecontroller can be implemented by other types of logic circuitry (e.g.,discrete components or programmable logic arrays) using a state machinetype of design, but a microprocessor-based system is preferable. Thecontroller is capable of operating the defibrillator 1600 in a number ofprogrammed modes where a programmed mode defines how pulses are outputin response to sensed events and expiration of time intervals.

A telemetry link 1680 is provided for communicating with an externalprogrammer 1675 and shock deferral device (see, for example, elements170 of FIG. 1, 300 of FIGS. 3 and 400 in FIG. 4). In one example thesame telemetry mode (e.g. RF) is used between defibrillator 1600 andexternal programmer 1675 and shock deferral device. In another example adifferent telemetry mode is used between defibrillator 1600 and externalprogrammer 1675 (e.g. inductive) and shock deferral device (e.g. RF).The external programmer is a computerized device with a controller 1677that can interrogate the defibrillator 1600 and receive stored data aswell as adjust the operating parameters of the pacemaker.

The defibrillator 1600 has an atrial sensing/pacing channel comprisingring electrode 1633A tip electrode 1633B sense amplifier 1631, pulsegenerator 1632, and an atrial channel interface 1630 which communicatesbi-directionally with a port of microprocessor 1610. The device also hastwo ventricular sensing/pacing channels that similarly include ringelectrodes 1643A and 1653A tip electrodes 1643B and 1653B senseamplifiers 1641 and 1651, pulse generators 1642 and 1652, andventricular channel interfaces 1640 and 1650. For each channel, theelectrodes are connected to the defibrillator 1600 by a lead and usedfor both sensing and pacing. A MOS switching network 1670 controlled bythe microprocessor is used to switch the electrodes from the input of asense amplifier to the output of a pulse generator. A shock channel isalso provided comprising a shock pulse generator 1690 and shockelectrodes 1691A and 1691B that enables the device to deliver adefibrillation shock to the heart when fibrillation or othertachyarrhythmia is detected. The defibrillator 1600 also has an evokedresponse sensing channel that comprises an evoked response channelinterface 1620 and a sense amplifier 1621 that has its differentialinputs connected to a unipolar electrode 1623 and to the device housingor can 1660 through the switching network 1670. The evoked responsesensing channel may be used to verify that a pacing pulse has achievedcapture of the heart in a conventional manner or, as explained below,used to record an evoked response electrogram.

The channel interfaces include analog-to-digital converters fordigitizing sensing signal inputs from the sensing amplifiers, registersthat can be written to for adjusting the gain and threshold values ofthe sensing amplifiers, and, in the case of the ventricular and atrialchannel interfaces, registers for controlling the output of pacingpulses and/or adjusting the pacing pulse energy by changing the pulseamplitude or pulse width. The microprocessor 1610 controls the overalloperation of the device in accordance with programmed instructionsstored in memory. The sensing circuitry of the defibrillator 1600generates atrial and ventricular sense signals when voltages sensed bythe electrodes exceed a specified threshold. The controller theninterprets sense signals from the sensing channels and controls thedelivery of paces in accordance with a programmed pacing mode. Thesensed signals from any of the sensing channels of the defibrillator1600 in FIG. 5 can be digitized and recorded by the controller toconstitute an electrogram that can either be transmitted via thetelemetry link 1680 to the external programmer 1675 or stored for latertransmission. The patient's cardiac activity may thus be observed inreal-time or over a selected historical period.

It should also be noted that, as used in this specification and theappended claims, the phrase “configured” describes a system, apparatus,or other structure that is constructed or configured to perform aparticular task or adopt a particular configuration. The phrase“configured” can be used interchangeably with other similar phrases suchas “arranged”, “arranged and configured”, “constructed and arranged”,“constructed”, “manufactured and arranged”, and the like.

All publications and patent applications in this specification areindicative of the level of ordinary skill in the art to which thepresent technology pertains. All publications and patent applicationsare herein incorporated by reference to the same extent as if eachindividual publication or patent application was specifically andindividually indicated by reference.

This application is intended to cover adaptations or variations of thepresent subject matter. It is to be understood that the abovedescription is intended to be illustrative, and not restrictive.

We claim:
 1. A shock deferral unit comprising: a bi-directionalcommunication device configured to receive a notification of animpending shock from a defibrillator and configured to send aninstruction to defer the impending shock to the defibrillator; anauthentication interface configured to receive authentication data froma user; a user instruction interface configured to receive theinstruction to defer the impending shock from the user; and anauthentication device configured to authenticate the user based on theauthentication data and instruct the bi-directional communication deviceto send the instruction to defer a shock upon authentication and receiptof the instruction to defer the shock, wherein the shock deferral unitis portable by an ambulatory patient, and wherein the authenticationinterface is configured to receive authentication data from a user andthe user instruction interface is configured to send the instruction todefer shock within a 60-second time period.
 2. The shock deferral unitof claim 1, wherein the bi-directional communication device is a radio.3. The shock deferral unit of claim 1, further comprising a userinterface configured to display the notification of the impending shock.4. The shock deferral unit of claim 3, wherein the bi-directionalcommunication device is configured to relay one or more physiologicalmeasurements sensed by the defibrillator to the user interface.
 5. Theshock deferral unit of claim 1, wherein the shock deferral unit isconfigured to be at least one in the group consisting of: wearable by,manually holdable by, and pocketable by a patient.
 6. The shock deferralunit of claim 1, wherein the authentication interface is configured toreceive at least one type of authentication data from the user in thegroup consisting of: textual, verbal, haptic, and biometric data.
 7. Ashock deferral system comprising: a defibrillator configured to sensepatient physiological measures, communicate a notification of impendingshock, and deliver shock therapy; and a bi-directional communicationdevice configured to receive a notification of impending shock from thedefibrillator and configured to send an instruction to defer theimpending shock to the defibrillator; an authentication interfaceconfigured to receive authentication data from a user; a userinstruction interface configured to receive the instruction to defer theimpending shock from the user; and an authentication device configuredto receive the authentication data from the authentication interface,and authenticate the user based on the authentication data; wherein thedefibrillator is configured to defer shock upon authentication by theauthentication device and receipt of the instruction to defer the shock,wherein the authentication interface and the user instruction interfaceare portable by an ambulatory patient, and wherein the authenticationinterface is configured to receive authentication data from a user andthe user instruction interface is configured to send the instruction todefer shock within a 60-second time period.
 8. The shock deferral systemof claim 7, wherein the defibrillator comprises the authenticationdevice.
 9. The shock deferral system of claim 7, wherein theauthentication device is configured to authenticate the user each timethe shock deferral unit receives a notification of impending shock fromthe defibrillator.
 10. The shock deferral system of claim 7, wherein thebi-directional communication device is configured to relay one or morephysiological measurements sensed by the defibrillator to a userinterface.
 11. A method comprising: relaying a notification of impendingshock therapy from a defibrillator to a user interface, wherein the userinterface is portable by an ambulatory patient; receiving authenticationdata from a user through an authentication interface in response torelaying the notification; authenticating the user with the receivedauthentication data; receiving an instruction from the user to defer theimpending shock therapy through a user input device; and sending thereceived instruction to the defibrillator to defer the impending shocktherapy upon authentication, wherein receiving authentication data froma user occurs within 60 seconds of relaying the notification ofimpending shock.
 12. The method of claim 11, wherein the authenticationinterface is at least one in the group consisting of: a biometricsensor, a microphone, and a manual user data entry device.
 13. Themethod of claim 11 further comprising relaying a notification of atleast one of: physiological measurements sensed by the defibrillator andshock deferral status to the user interface.
 14. The method of claim 11wherein the instruction from the user is received through at least oneof: a watch, a pendant, a bracelet, eyeglasses, headphones, a mobilephone, a pen, a card, a box, and an adhesive accessory.
 15. The methodof claim 11 wherein sending the received instruction to thedefibrillator is through radio frequency.
 16. The method of claim 11further comprising entering a training mode comprising soliciting a userfor authentication data absent a notification of impending shocktherapy.